Rails on Windows: Slow?

I've tried 18.6, 1.8.7 and 1.9.1 on Window, OS X and Linux. I have found the response time using Windows to be longer than using either OS X or Linux (Webbrick and Mongrel). If I use Windows purely as a server, response time seems as OS X Linux, but much slower if I develop and render result using any browser whilst using the same computer.